A56-F-R-00-H-S-K-D24-32408 YUKEN Piston Pump

Product Overview

The YUKEN A56 Series Variable Displacement Piston Pump is a swash-plate axial piston pump designed for hydraulic systems requiring adjustable displacement, efficient operation and controlled pressure performance.

YUKEN’s official documentation confirms a 56.2 cm³/rev geometric displacement for the A56 frame. The standard 01 configuration is identified as a Pressure Compensator Type, while the current YUKEN Europe product range continues to list A56 pumps from 12 to 56.2 cm³/rev.

The supplied product group contains:

• A56-F-R-00-H-S-K-D24-32408
• A56-F-R-01-B-K-32
• A56-F-R-01-C-K-32
• A56-F-R-01-H-K-32

The B/C/H variants are different pressure-adjustment configurations, not one single complete model number.

For A56-F-R-00-H-S-K-D24-32408, the public YUKEN documentation confirms the A56 00 family, H pressure range, clockwise R rotation, flange mounting and keyed shaft architecture. However, the publicly available standard catalogue does not provide a reliable field-by-field interpretation of the special D24-32408 suffix. Therefore, those suffixes should be verified against the original nameplate or drawing before contractual specification.

Our replacement engineering process focuses on in-place interchangeability and 100% simulated working-condition testing, rather than displacement matching alone.

Technical Specifications (Bulleted List)

A56-F-R-00-H-S-K-D24-32408

• Brand: YUKEN
• Series: A Series
• Frame size: A56
• Model: A56-F-R-00-H-S-K-D24-32408
• Pump type: Variable displacement piston pump
• Geometric displacement: 56.2 cm³/rev
• Control family: 00 — Special Control Type
• Pressure adjustment range: H — 1.2–21 MPa / 12–210 bar
• Rotation: R — clockwise, viewed from shaft end
• Mounting: F — flange mounting
• Shaft: K — keyed shaft
• Port position: S appears in the supplied special code and corresponds to side-port configurations in YUKEN A-series coding; final confirmation should follow the actual drawing.
• Rated pressure: 16 MPa
• Intermittent / maximum pressure: 21 MPa
• Allowable shaft speed: 600–1800 r/min for the standard A56 00 family
• Large-displacement adjustment range: approximately 9–56.2 cm³/rev
• Small-displacement adjustment range: approximately 3–27.7 cm³/rev
• Weight: not confirmed for the specific D24-32408 special configuration
• D24: not sufficiently defined in the public standard YUKEN catalogue
• 32408: special design/reference suffix not fully decoded in the public YUKEN catalogue

YUKEN’s official documentation states that the A56 00 configuration does not provide full cut-off and requires an external relief valve on the discharge circuit to establish maximum circuit pressure.

A56-F-R-01-B-K-32

• Brand: YUKEN
• Series: A Series
• Model: A56-F-R-01-B-K-32
• Geometric displacement: 56.2 cm³/rev
• Control type: 01 — Pressure Compensator Type
• Pressure adjustment range: B — 1.2–7 MPa / 170–1020 psi
• Rotation: R — clockwise
• Mounting: F — flange mounting
• Shaft: K — keyed shaft
• Design number: 32
• Minimum adjustable flow: 12 cm³/rev
• Rated pressure: 16 MPa
• Intermittent / maximum pressure: 21 MPa
• Allowable speed: 600–1800 r/min
• Approximate mass: 35.0 kg for the standard flange-mounted A56 configuration.

A56-F-R-01-C-K-32

• Brand: YUKEN
• Series: A Series
• Model: A56-F-R-01-C-K-32
• Geometric displacement: 56.2 cm³/rev
• Control type: 01 — Pressure Compensator Type
• Pressure adjustment range: C — 1.2–16 MPa / 170–2320 psi
• Rotation: R — clockwise
• Mounting: F — flange mounting
• Shaft: K — keyed shaft
• Design number: 32
• Minimum adjustable flow: 12 cm³/rev
• Rated pressure: 16 MPa
• Intermittent / maximum pressure: 21 MPa
• Allowable speed: 600–1800 r/min
• Approximate mass: 35.0 kg for the standard flange-mounted A56 configuration.

A56-F-R-01-H-K-32

• Brand: YUKEN
• Series: A Series
• Model: A56-F-R-01-H-K-32
• Geometric displacement: 56.2 cm³/rev
• Control type: 01 — Pressure Compensator Type
• Pressure adjustment range: H — 1.2–21 MPa / 170–3050 psi
• Rotation: R — clockwise
• Mounting: F — flange mounting
• Shaft: K — keyed shaft
• Design number: 32
• Minimum adjustable flow: 12 cm³/rev
• Rated pressure: 16 MPa
• Intermittent / maximum pressure: 21 MPa
• Allowable speed: 600–1800 r/min
• Approximate mass: 35.0 kg for the standard flange-mounted A56 configuration.

YUKEN Europe currently lists the A56 pressure-compensated A Series configuration in the 12–56.2 cm³/rev displacement range, with the H pressure setting covering 12–210 bar.

Key Technical Advantages

1. 56.2 cm³/rev Variable Displacement Architecture

The A56 uses a swash-plate axial piston architecture in which displacement changes with the swash-plate angle. YUKEN positions the A Series around high efficiency, low noise and a broad choice of displacement and control configurations.

At the theoretical maximum displacement of 56.2 cm³/rev and 1800 r/min, the calculated theoretical flow is approximately 101.2 L/min. This is a geometric calculation, not a guaranteed delivered flow rate under load.

2. Pressure Compensation for Stable Hydraulic Operation

The 01 control code identifies the Pressure Compensator Type.

As system pressure approaches the preset value, pump displacement decreases automatically, reducing unnecessary output flow while maintaining the required pressure. This is particularly useful in hydraulic systems with changing actuator demand.

3. Three Pressure-Adjustment Options

The A56 01 family provides:

• B: 1.2–7 MPa
• C: 1.2–16 MPa
• H: 1.2–21 MPa

The correct pressure-range code must be retained during replacement because it directly affects pressure compensation settings.

4. High Efficiency and Low Noise

YUKEN’s official A Series documentation describes the pumps as high-efficiency, low-noise swash-plate variable piston pumps. Precision relationships between the piston group, cylinder block, valve plate, bearings and control mechanism influence internal leakage, efficiency, pressure ripple and acoustic performance.

5. Keyed Shaft and Installation Interface Matching

K identifies a keyed shaft in the A-series ordering system.

For genuine replacement interchangeability, the following must be checked together:

displacement + rotation + control + pressure range + mounting + shaft + port arrangement + design number

A nominally identical 56.2 cm³/rev pump is not automatically interchangeable.

6. Special 00 Control Configuration

YUKEN’s official catalogue identifies 00 as a Special Control Type. The A56 00 configuration belongs to the two-pressure/two-flow control family, and YUKEN specifies that it does not provide full cut-off. An external relief valve is therefore required on the discharge circuit for maximum system-pressure protection.

7. 100% Simulated Working-Condition Testing

For replacement A56 units, the test program can include:

• Startup and low-speed operation
• 600 r/min minimum-speed condition
• 1800 r/min rated-speed condition
• Maximum displacement
• Pressure-compensator response
• B/C/H pressure setting verification
• External relief protection
• Case leakage
• Oil-temperature rise
• Continuous-load operation

This converts simple dimensional matching into practical functional interchangeability.

Application Areas

YUKEN identifies the A Series as a standard variable piston pump platform developed for energy-efficient, low-noise hydraulic systems and a wide range of industrial hydraulic applications. YUKEN’s industrial portfolio covers machine tools, plastic machinery, hydraulic power units and other industrial equipment.

Typical A56 applications include:

• Industrial hydraulic power units
• Machine-tool hydraulic systems
• Press auxiliary hydraulic systems
• Plastic machinery
• Hydraulic clamping systems
• Multi-actuator hydraulic circuits
• Industrial automation equipment
• Hydraulic replacement projects
• Legacy YUKEN A56 installations

Final machine compatibility should be verified from the complete model code, mounting dimensions, control circuit and original nameplate.

Expert Maintenance Tips

Verify Rotation Before Commissioning

R means clockwise rotation, viewed from the shaft end.

Confirm the prime-mover rotation and pump rotation before startup.

Verify the B/C/H Pressure Code

Do not treat all A56 pressure-compensated pumps as equivalent:

• B = 1.2–7 MPa
• C = 1.2–16 MPa
• H = 1.2–21 MPa

These are part of the pump’s ordering and hydraulic-setting configuration.

Provide External Pressure Protection for 00

YUKEN states that the 00 configuration does not have a full cut-off function. The discharge circuit therefore requires an external relief valve to establish the maximum system pressure.

Respect the 600–1800 r/min Speed Range

The standard A56 documentation specifies an allowable speed range of 600–1800 r/min. Commissioning should therefore remain inside the applicable speed limits.

Keep the Filling Port Correctly Oriented

YUKEN’s A56 dimensional documentation specifies installation with the filling port at the top. The A56 design also provides two drain-port positions; one may be selected for use while the unused port must be properly plugged.

Control Hydraulic Contamination

The piston group, cylinder block, valve plate and bearing system operate with controlled internal clearances. After pump replacement, clean the reservoir and lines, inspect filtration and remove contamination before commissioning.

Do Not Invent Material Grades

The publicly available YUKEN A56 documentation reviewed does not provide enough evidence to state specific housing, cylinder-block or piston material grades. For technical marketing, it is more accurate to emphasize:

precision machining + controlled clearances + surface quality + assembly consistency + contamination control

rather than publishing unverified material or heat-treatment claims.